The present invention relates to a method of simultaneously closing pairs of boxes.
In particular, the present invention relates to a method of folding, substantially simultaneously, two pairs of tabs forming part of two superimposed boxes.
The present invention is especially suitable for packing machines, particularly those designed for producing pairs of boxes substantially in the form of a rectangular parallelepipedon.
Purely by way of example, the following description refers specifically to cigarette manufacturing machines, in particular, cartoning machines for producing cartons of cigarettes consisting of two half cartons, each comprising a rectangular parallelepiped box normally containing a row of five packets of cigarettes, and which may or may not be joined to the box of the other half carton.
On known machines of the aforementioned type, the half cartons are produced from respective preferably substantially identical blanks, which are each folded in a U about the respective row of packets, so as to present two longitudinal or lateral tabs projecting transversely, and a number of end tabs projecting axially in relation to the packets. The end tabs are normally folded for closing the longitudinal ends of the respective half carton using known folding devices, while further known devices are used for folding the lateral tabs one on top of the other.
On known machines of the aforementioned type, due to the difficulties posed in simultaneously forming the two boxes in each carton, these are normally closed separately and then placed and joined one on top of the other to form the finished carton. The major difficulty encountered in this respect is in folding the lateral tabs when the two boxes are placed substantially one on top of the other.